The subject matter disclosed herein relates to integrated drive generators (IDGs), and more specifically, to an IDG carrier shaft set.
In a conventional IDG system, a drive shaft connectable to an output shaft driven by an aircraft engine is connected to a mechanical differential, with the differential having an output connected to drive the generator. A variable speed transmission, such as a hydrostatic transmission or log, is associated with the mechanical differential and controlled to modify the output of the differential, as required, whereby the input speed to the generator remains constant even though the speed of the drive shaft may vary. There are a variety of structural arrangements for a constant speed drive and generator system.
A carrier shaft assembly can support a number of loads associated with driving the IDG through a planetary gear system disposed within and about a carrier shaft set that includes a carrier shaft and an input carrier shaft. A carrier shaft set is typically designed with symmetrical machining about a principle axis. When the carrier shaft assembly is oriented in operation to rotate about an operational axis that is different than the principle axis, a rotational load imbalance imparts additional forces. Imbalanced bearing loads can lead to premature wear and/or failure. Accordingly, there is a need for a carrier shaft set and assembly that reduce rotational load imbalance in an IDG system.